WASHINGTON ― Andy Slavitt helped save Obamacare once already. He’s hoping he can do it again.

Until Inauguration Day, Slavitt had been acting administrator of the Centers for Medicare and Medicaid Services since March 2015. That agency oversees the two health programs in its name along with the Children’s Health Insurance Program and the Affordable Care Act’s health insurance exchanges. CMS, as it’s known, manages benefits for 140 million people and its $1 trillion budget is bigger than the Pentagon’s.

In the short time since Slavitt left federal service, he’s already seeing signs that President Donald Trump and the GOP Congress are dealing damage to the health care system before even repealing the Affordable Care Act. And health care executives are telling him the same thing, Slavitt said.

“I take the new president at his word. He said he wants to expand coverage. He said he wants the coverage to be high-quality. He said he wants it to be affordable to Americans who have trouble affording health care,” Slavitt said. “Those are the right goals, and I think the president should start out with those goals. Now, the actions that we’ve seen so far don’t support those goals.”

The number one thing you hear people say is they’re petrified of the consequences of repealing the ACA without already approving a plan.Andy Slavitt

Specifically, Slavitt cited the executive order Trump issued the day of his inauguration, which instructs federal agencies to “take all actions consistent with law to minimize the unwarranted economic and regulatory burdens of the Act, and prepare to afford the States more flexibility and control to create a more free and open healthcare market.”

The White House subsequently signaled this could include halting enforcement of the law’s individual mandate that most Americans obtain health coverage.

Executive actions such as these, and like the Trump administration halting television advertising for the sign-up period that ends Tuesday, threaten to destabilize the health insurance market, Slavitt. These moves signal to health insurers that enrollment will be lower this year than it could have been, and that fewer of the healthy consumers needed to offset the costs of the sick will buy coverage. Without the mandate’s tax penalty for being uninsured, some consumers will opt against buying insurance.

“It increases premiums, it will send people out of the market,” Slavitt said. “Those actions that we’ve seen haven’t gotten us on the track that we would hope and that we need to be on in a bipartisan fashion, and so I’d hope that they’re quickly corrected.”

But the current “repeal and delay” strategy ― under which the law is repealed but not replaced for several years while Congress debates an alternative to Obamacare ― creates uncertainty about the future of the health care system that could severely damage it, he said.

Although he’s left government, Slavitt remains in contact with policymakers and with health care executives whose companies would be affected by whatever short-term and long-term changes are made to the Affordable Care Act. They’re worried, he said.

“I’ve been talking to a lot of hospital CEOs, a fair number of governors, health plan CEOs. I think the number one thing you hear people say is they’re petrified of the consequences of repealing the ACA without already approving a plan. Not introducing a plan, but approving a plan that helps them know what comes next,” Slavitt said.

“A fifth of the economy is dependent on the decisions that you make, in many respects,” Slavitt said. “Saying we may do this, we may not do that, we’re unsure about this, we’re looking like we’ll do that ― is very harmful.”

The skittishness on display among Republicans about how to repeal Obamacare without causing that harm and without facing a huge backlash from taking away health coverage from more than 30 million people gives Slavitt hope that Congress and the new administration, along with state leaders, will find a better way to move forward.

“I know there’s a lot of people who are very worried. They’re very scared. I hear from them every day. We heard from them in the thousands over the course of November and December and January. I still hear from them,” Slavitt said.

“I would say that this course, this course of repeal and delay, is not a done deal,” Slavitt said. Recent polling has shown an increase in public support for the Affordable Care Act, and the belief that Congress shouldn’t undo the law without showing the American people what Republicans want to do instead.

Slavitt also criticized some of the GOP proposals circulating that would attempt to address the cost of health insurance by simply having it cover fewer medical costs and require patients to shoulder a greater share of the expenses out of pocket, even compared to the high-deductible plans offered on the Affordable Care Act’s health insurance exchanges.

The Affordable Care Act requires insurers to cover a basic set of services, including hospitalizations, prescription drugs and contraception. Relaxing those requirements theoretically could lower monthly premiums, but it also would expose policyholders to the full cost of whatever isn’t covered by the insurance, Slavitt said.

“What we have to be careful of is the certainty that people think they’re buying is a good thing. And so the talk of patient choice, across state lines, all of these things, the hazard there, of course, is that you really deteriorate what insurance is,” Slavitt said.

“Health care is expensive. It’s not that health insurance premiums are just too high, it’s that the health care is too expensive. So if you make the health [insurance] cover less, it doesn’t make anything less expensive. In fact, it makes it more expensive,” he said.

“How do you know you don’t need mental health services? You don’t need it until you need it. And I think that’s the great fallacy that gets perpetuated with this idea that you can go a la carte and exclude benefits that you think you don’t need.”

The Affordable Care Act made major strides in improving the health care system, most visibly by reducing the uninsured rate to a historic low. Whatever comes next must be measured by the same standards and seek to improve the health law’s shortcomings, not create more problems, Slavitt said.

It’s not that health insurance premiums are just too high, it’s that the health care is too expensive.Andy Slavitt

”The record is good. What we need now ― we need more competition and more affordability. And so, actions that will promote affordability and promote competition, I think, will head us the right direction. Actions which destabilize the market, create uncertainty, open up a sort of free-for-all will set us in the wrong direction. I think that’s the choice we have right now,” Slavitt said.

“Good ideas that improve the ACA are things that I will applaud and cheer no matter where they come from,” Slavitt said. “But they have to meet some basic tests. They have to help us cover more people, they have to do it with high-quality coverage, and they have to do it in a way that helps us continue to bend the cost curve, not increase it, and they have to do it in a fiscally responsible way.”

Watch The Huffington Post’s full interview with Andy Slavitt. Video produced by J.M. Rieger and Jessica Carro.